Almost four years have passed since the rosdistro file format has been last updated in REP 143. The latest REP draft aims to add a small piece of additional information to the index.yaml file. For each ROS distribution the major ROS version should be annotated, e.g. for ROS Melodic that would be 1 and for ROS Bouncy that would be 2. Currently that information is not available anywhere and therefore hardcoded in various places. Please see the current draft of the REP for the fairly small addition.
While the change is small it still requires a bump of the index file format from version 3 to version 4. That will ensure that once the rosdistro repository is being updated to include this information that users which are still using an “older” version of the Python rosdisto package will get a meaningful error message guiding them to update the rosdistro Python package.
After the REP has been rolled out and the rosdistro repository has been updated to annotate the ROS distribution we will be able to consolidate the forked ROS 2 rosdistro repository into the upstream one. This will make releasing ROS 2 repositories as simple as it is for ROS 1 - without the need for a custom environment variable.
Please provide your feedback on the REP pull request. (Please do not reply in this discourse thread since the audience is very big and not everyone might be interested in the in-depth discussion of this topic.)
Your friendly ROS team